Steerable vehicle truck



July 23, 1940. A, RQNN|NG 2,208,601

. STEERABLE VEHICLE TRUCK Filed Dec. 5, 1938 2 Sheets-Shet Ilv INVENTOR/D/f @GNN/N6 ATTORNEY Patented July 23,1940

UNITED STATES PATENT OFFICE 19 Claims.

, This invention relates to steerable supporting units vor trucks forwheeled vehicles, vparticularly of the self-propelled type, and theprimary object is to provide a novel, Aeilicient, and practical meansfor mounting a pair of closely spaced wheels so that they will steerabout a common or central vertical axis but yet have freedom forrelatively vertical or up and down movement. to equalize load stressesto the two wheels, and whereby such equalizing or dierential action willgreatly facilitate the steering' action. particularly when the vehicleis traveling and making g 242,726, both led- November 28th, 1938, and t0Serial No. 247,608, filed December 24, 1938; and Serial No. 250,344 and250,345, led January 11, 1939. y

In the accompanying drawings, illustrating' a '25 preferred embodimentofthe present inventive concept- Fig. 1 is a side elevation of the forepart of a tractor illustrating the application of my improved steeringtruck. Fig. 2 is a front elevation of the tractor as shown in Fig. 1,and with a part of the steering mechanism in section.

Fig. 3 is an enlarged front end elevation of the housing used inmounting the Wheels, but with the wheels removed from the extended stubshafts.

Fig. 4 is a side elevation of the housing with one side section removedto expose the differential mechanism.

Fig. 5 is across. section through the housing and enclosed parts, as online 5 5 of Fig. 3.

Fig. 6 is a longitudinal vertical sectionthrough a modified form ofthedevice.

Fig. 7 is a horizontal section on line I-l in 45 Fig. 6. V

Fig. 8 illustrates a tandem arrangement of tractors in which thesteerable truck of the rear tractor is attached to the draw bar of theforward tractor in such a manner that the tractors may 50 trail and beguided one behind the other and Without interfering with the verticalaction of the truck wheels so guided.

The'structure illustrated in Figs. 6 and 7, and applied in Fig. 8, isidentical with subject matter 55- illustrated in but divided out from myaforesaid application Serial No. 219,369, and to that extent the presentapplication is considered as a continuation in part from said otherapplication.

Referring to the drawings more particularly 00 and by referencecharacters, A designates the frame of a tractor in the front end ofwhich is secured a vertical bearing B in which is journaled a steeringpost C. At its rear the tractor vis provided With theusual transverselyspaced traction wheels D, as shown at the right in Fig. 8, which notonly support the rear end but also impart the necessary lateralstability. As shown in Fig. 2, the upper end of post C has a worm gearE, operated by worm F on shaft G, and which shaft is in turn rotated byhand Wheel H (Figs. 1 and 8) manipulated by the tractor operator on seatI. When the tractors are operated inv tandem arrangement the steeringwheel H of the rear tractor is not used. vIn this case a draft link 9connects the steerable truck of the rear tractor to the draw bar J ofthe front tractor so that the forward or angular position of the fronttractor will guide such truck to steer the rear tractor, and in thiscase it may further be noted that the worm drive E-F is so pitched thatthe teeth will not lock but will be free to rotate in response to thesteering action imparted by the connecting link 9.

Referring now to Figs. 1-5, it will be seen that the bearing sleeve B issupported on the neck I0 of a housing II made up of two ,complementalsections rigidly secured together by bolts I2. The neck portion I0 isrigidly secured to the `lower end of the post so as to turn with itabout the post axis.

The ground wheels'K, preferably of the pneumatic tire type, are closelyspaced inasmuch as they are not designed to give lateral stability tothe tractor and also because it is desirable to have them travel betweencrop rows when thetractor is to be used for row crop work. Thesev wheelsare mounted on spindles I3, extendingrigidly from the rear ends of crankarms I 4 and I5, dis# posed at opposite sides of the housing I I andprovided at their forward ends with stub shafts I6 and Il, respectively,which extend co-axially into the housing and are joumaled inanti-friction bearings I8. The spindles. I3 are slightly slopedoutwardly, as shown in Fig. 3, togive the desired camber to the wheels,as indicated in Fig. 2. It shouldV be noted,l however, that any relativeup and down movement of the wheels and cranks, about the axes of stubshafts lli-I1, will not disturb either the fixed camber angle of thewheels or their relative angle with respect to the steering post,- norwill they produce any relatively l transverse motion as between thewheels that would result in transverse frictional ground contact. Itshould also be noted that while the housing II projects forwardly fromneck I0, the cranks I4-I5 both extend rearwardly, with a result that theaxes of the wheels K operate directly opposite the post C and in thevertical transverse plane thereof, and consequently ,their vsectors areoperatively connected through an intermeshing, intermediate bevel gearpinion 20. This pinion Ihas an integral stub extension 2I which journalsin a bore 22 of the housing. The

member 2li-2l may be conveniently provided with a duct 23 by which oilcontained in housing II may be conducted to the gearing bore 22 tolubricate the same.

It will be understood that as the weight of the front end of the tractoris imposed on the housing iIl-I i it will be transmitted to the wheels Kvthrough the gears Iii-20, shafts I6-Il', cranks I4I5, and spindles I3,all of which will remain relatively stationary when traveling over levelterrain. When uneven ground surface is encountered, however, asindicated in Figs. l and 2, then the pinion 20 will differentiallyfunction to permit the wheels to assume relative vertical positions, onegear (I8 or I9) and its associated crank (I4 or I5) being free tooscillate upwardly while the other moves correspondingly downwardly,while at the same time continuing to distribute the applied tractorweight evenly to both wheels.

There' is, of course, a limit to the relative vertical movements of thewheels, and to eliminate objectionable -jars or destructive contactswhen such Vmovement limits are reached, I provide shock absorber orbumper in the form of springs 24 (Figs. 4 and 5). Each of these springsis anchored at its middle, as at 25, to the front wall of the housing,

I I, and its upper and lower ends extend resiliently' forward to contactthe respective upper and lower ends of the adjacent gear segment andthereby yieldingly restrain forward movement thereof as the groundwheels approach their maximum limits of vertical movement.

, It may here further be noted that the spliningof the shafts vI6 and I1in the respective gear segments is such that by removing nuts 26, afterhousing II has been opened, the segments can be removed and resecured onthe shafts in selectively rotated positions, with a result that thecomposite or normal working angles of cranks I4-I5 may be adjusted whennecessary. This adjustment is also of course operative to regulatetheelevation of the tractor with respect to both of thewheel spindlesI3.

In the 'embodiment of the invention as exemplified by Figs. 6, 7, and 8,the gear case or housing 21 has a neck 28 fixed to the lower end of postC by pin 29. The casing is preferably of solid or integral constructionthroughout except for a bottom opening shown as closed by a cover plate21a, secured by bolts 30. In this case the cranks 3land 32, whichsupport the wheel spindles I3, extend forwardly and rearwardly,respectively, from the stub shafts 33 and 34 that are journaled inopposite, fore and aft ends of the housing, so that, as before, the axesof the wheels will be disposed centrally or in the transverse verticalplane of the steering post C.

Non-rotatably secured on the shafts 33, 34, an within the housing, is apair of spur gear segments 35connected by an intermediate, intermeshingspur gear 36 which, it will be seen, has the same compensating action ordifferential function as that described in connection with the pinion 23of Figs. 1 5.

Itwill be noted that the housing closure plate 21a is'provided with apair of depending lugs 31 aaoacoi adapted'to receive bolts 38 whichrigidly secure to the plate a forwardly extending bar 39. The rear endof draft bar 9 is pivoted to this bar 39, as at 40, so that the draftbar can swing vertically but when swung to either side will turn thehousing 2l with it to thereby steer the ground wheels K when thetractors are connected in tandem as shown in Fig. 8. The forward end ofthe draft bar 9 is universally connected, as at di, to the draw bar J ofthe tractor so as to provide for the necessary flexibility of movementat this point.

It may be mentioned that in the arrangement illustrated in Fig. 8 therear vehicle'would not necessarily have to be a tractor as a steerabletruck embodying my improved features could as well be applied to anykind of drawn vehicle or wheeled implement. v

Referring back to Figs. 3 and 4, it will be seen that I have there alsoprovided means in the form of a depending flange I Ia, by which asimilar trailer attachment might be connected with to apply draft powerdirectly to the steerable truck in that case.

It is understood that suitable modifications may be made in thestructure as disclosed, provided such modifications come within thespirit and scope of the appended claims. Having now therefore fullyillustrated and described my invention, whatI claim to be new and desireto protect by Letters Patent is:

1. In a vehicle, a steerable truck supporting one is substantiallycoincident witha vertical plane through the axes of the wheels, and gearmeans differentially connecting the cranks causing them to oscillate inopposite vertical directions.

2. A steerable vehicle supporting truck comprising a member mounted foroscillation about a generally vertical axis to elect steering, a pair ofcranks journaled inthe member for simultaneous movement therewith aboutsaid axls, ground wheels rotatably secured to said cranks, and gearmeans differentially connecting the journaled ends of the cranks andoperative to cause opposite up and down movements thereof and to causethe imposed vehicle weight to be transmitted lengthwise through thecranks and equally distributed to the wheels when and as the trucktravels over irregular ground surfaces.

3. A steerable vehicle supporting truck coming member, one at each sidethereof, for oscillating movements, and a gear train differentiallyconnecting said wheel supported members.

5. In a steering truck for vehicles, a mounting member rotatable aboutan upright axis, a pair of wheel supported cranks carried at oppositesides of the member for oscillation about respective axes spaced withrespect to each other, a pair of gear segments connected one with eachof said cranks, and a gear member interposed between and diiferentiallyconnecting said gear segments.

6. In a steering truck for vehicles, a mounting member rotatable aboutan upright axis, a

pair of Wheel supported cranks carried at opv posite sides of the memberfor oscillation about a common axis, a pair of opposed bevel gearsegments connected one with each crank, and a bevel pinion meshing withand differentially operating the gear segments.

7. In a vehicle, a mounting member, a pair of cranks oscillatablyjournaled in the mounting member, one at each side thereof, a pair ofgear segments attached to the respective cranks to oscillate therewith,means for adjustably attaching one of the segments to the correspondingcrank whereby the crank and segment may be relatively adjusted about thecommon axis thereof, and a gear member diierentially connecting thesegments.

8. In a vehicle adapted to be drawn, a steerable truck supporting thefront end thereof and comprising a mounting member movable about avertical axis, a pair of wheels mounted one at each side of the memberfor opposite up and down movements while retaining predetermined faceangles with respect to said axis, means, operative from a position onthe vehicle, for turning the mounting to steer the wheels, and draftmeans, independent of said turning means, extending forwardly from thetruck for applying pulling and steering action thereto.

9. A Vehicle supporting device comprising a housing, a pair of wheelsupported crank arms journaled in the housing, and gear means in thehousing differentiallyv connecting the journaled ends of the crank arms,said crank arms being journaled for movement about longitudinally spacedaxes and extending in opposite directions therefrom.

10. In a vehicle, a pair of crank arms journaled at longitudinallyspaced outer ends with respect to the vehicle and with their inner endsseparately supported on axially aligned wheels, a pair of gear segmentsconnected lwith the respective crank arms, andY an intermediate -geardifferentially connecting the segments.

11. In a vehiclefa housing mounted thereon to support the same andincluding two separable sections, a pair of crank arms journaled one ineach of said housing sections to support the housing, ground wheelssupporting the respective cranks, and differential mechanism connectingthe arms within the housing to move them and their respective wheels inopposite directions.

12. A steerable vehicle supporting truck comprising a member mounted formovement about a generally vertical axis to effect steering, a pairprising a member mounted for movements about a generally vertical axisto effect steering,`a pair of cranks journaled in the member forsimultaneous movement therewith about said axis, ground lwheelsrotatably secured to said cranks and with their axes disposedapproximately in the transverse plane through .said generally verticalaxes, and a rotatable member differentially. connecting the cranks tooscillate the latter in opposite directions, said cranks being mountedfor oscillating movements about a common transverse axis and extendingin the same general direction therefrom.

14. A steerable vehicle supporting truck comprising a member mounted forrotation about a vertical axis to effect steering, a pairV of cranksjournaled in the member for simultaneous movement therewith about saidaxis, ground wheels rotatably secured to said cranks, and a rotatable'member differentially connecting the cranks to oscillate the latter inopposite up and down directions, said cranks being mounted foroscillating movements about longitudinally spaced transverse axes, andrespectively extending therefrom in generally opposite directions.

15. In a vehicle, a steerable truck therefor comprising a housingmounted for turning movement about a generally upright axis, a pair ofwheel supported cranks journaled in the housing for oscillatingmovements in up and down directions, Vand gear means in the housingdifferentially connecting the cranks.

16. In a vehicle, a steerable truck therefor comprising a housingmounted for turning movement about a generally upright axis, a pair oftransversely spaced Wheel supported cranks journaled in the housing foroscillating movements in longitudinally'extending planes, and

gear means in the housing differentially connecting the cranks, saidgear means including gear elements connected to the respective cranksand Aan intermediate gear element connecting said gear elements.

17. In a vehicle, a steerable truck therefor comprising a housingmounted for turning movement about a generally upright axis, a pair oftransversely spaced wheel supported cranks journaled in the housing foroscillating up and down movements, differentially acting gear meansconnecting the cranks, and yieldable stop means limiting `theoscillating movements of the cranks, said stop means including aresilient member cooperatively associated with the gear means.

18. In a vehicle having a frame, a pair of crank arms pivoted withrespect to the frame for movements in transversely spaced paths, groundwheels rotatably secured to the arms, diierential mechanism connectingpivoted ends of the arms and operative to distribute imposed vehicleweight equally through both arms to the respective wheels, and means foradjusting the mean working angle ofthe arms with respect to thehorizontal.

19. In a. vehicle having a frame, a pair of transversely spaced crankarms pivoted with respectto. the frame for oscillating movements whilesupporting the frame, ground wheels rotatably secured to the arms, gearacting elements connected to the respective arms and at least one ofwhich elements is adjustable with respect'to its arm so as to produceangular adjustments of both arms with respect to the horizontal andthereby vertically adjust the frame, and a --gear differentiallyconnecting said elements. l ADOLPH RONNING.

